Halogenated ethers containing fluorine and processes for their manufacture

ABSTRACT

A process is disclosed for preparing an adduct of the formula R 1  CF 2  CH 2  OCF 3-a-m  (C 2  H n  X 4-n  F) m  R 2   a  wherein R 1  is selected from the group consisting of --(CF 2 ) p  H and --C p  F 2p+1  where p is 0 or an integer from 1 to 6; R 2  is selected from the group consisting of --H, --CHF 2 , --CHFCF 3 , --CHFOCF 3 , --CHFO(CF 2 ) 2  CF 3 , and --CHClF; each X is independently selected from the group consisting of Br, Cl and F; a is 0 or 1; m is 1 or 2, provided that when a is 1 and R 2  is other than hydrogen, then m is 1; and n is 0, 1 or 2. The process involves reacting a fluorinated ether of the formula R 1  CF 2  CH 2  OCF 3-a  R 2   a  with an olefin of the formula C 2  H n  X 4-n  in the liquid phase in the presence of antimony pentafluoride catalyst. Also disclosed is a process for preparing unsaturated ethers of the formula R 1  CF 2  CH 2  OCF 3-a-m  (C 2  H n  X 4-n  F) m-q  (C 2  H n-1  X 3-n  F) q  R 2   a  wherein R 1 , R 2 , X, a, m, and n are as indicated above, and q is an integer from 1 to m. The process involves contacting the fluorinated ether of the formula R 1  CF 2  CH 2  OCF 3-a-m  (C 2  H n  X 4-n  F) m  R 2   a , provided that C 2  H n  X 4-n  F is selected from the group consisting of --CClFCClF 2 , --CCl 2  CCl 2  F, --CHClCCl 2  F, --CHClCHClF and --CCl 2  CHClF, with a dehalogenation catalyst. Certain unique saturated ethers of the formula R 1  CF 2  CH 2  OCF 3-a-m  (C 2  H n  X 4-n  F) m  R 2   a  and certain unique unsaturated ethers of the formula R 1  CF 2  CH 2  OCF 3-a-m  (C 2  H n  X 4-n  F) m-q  (C 2  H n-1  X 3-n  F) q  R 2   a  are also disclosed.

This application claims the priority benefit of U.S. Provisional Application 60/050,221, filed Jun. 19, 1997.

FIELD OF THE INVENTION

This invention relates to certain saturated and unsaturated halogenated ethers and processes for their manufacture by catalyzed addition reactions and/or catalyzed dehalogenation reactions.

BACKGROUND

Fluoroethers of the general formula R--O--CF--R¹ R² have been disclosed to react in the liquid phase upon contact with a Lewis acid (e.g., SbF₅) to yield hydrofluorocarbons R-F (U.S. Pat. No. 5,495,056). In the α-fluoroethers of the formula R--O--CF--R¹ R², the R group may generally take any form and may comprise heteroatoms (e.g., O, S or N) provided that it comprises at least one carbon atom. The R group may be saturated or unsaturated, linear or branched chain, cyclic or acyclic, aliphatic or aromatic. R¹ and R² are hydrogen, fluorine or optionally substituted alkyl groups. In an example, CH₂ FOCH₂ F is reacted with SbF₅ at 0° C. and CH₂ F₂ is obtained. It has also been shown that fluoroethers which contain the moieties, --CF₂ OCH₃ or --CF₂ OC₂ H₅, react with SbF₅ to give compounds which do not contain ethers but instead contain a fluoroacyl (--COF) group (U.S. Pat. No. 4,357,282). In an example, CHF₂ CF₂ OCH₃ is reacted with SbF₅ at room temperature and CHF₂ COF and CH₃ F are isolated.

Fluorinated ethers are useful as refrigerants, heat transfer media, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, displacement drying agents and power cycle working fluids. Olefinic fluoroethers are useful as monomers for fluoropolymers. There is an interest in developing more efficient processes for the manufacture of fluorinated ethers.

SUMMARY OF THE INVENTION

A process is provided for preparing an adduct of the formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m) R² _(a) wherein:

R¹ is selected from the group consisting of --(CF₂)_(p) H and --C_(p) F_(2p+1) where p is 0 or an integer from 1 to 6;

R² is selected from the group consisting of --H, --CHF₂, --CHFCF₃, --CHFOCF₃, --CHFO(CF₂)₂ CF₃, and --CHClF;

each X is independently selected from the group consisting of Br, Cl and F;

a is 0 or 1;

m is 1 or 2, provided that when a is 1 and R² is other than hydrogen, then m is 1; and

n is 0, 1 or 2.

The process comprises reacting a fluorinated ether of the formula R¹ CF₂ CH₂ OCF_(3-a) R² _(a) with an olefin of the formula C₂ H_(n) X_(4-n) in the liquid phase in the presence of antimony pentafluoride catalyst.

This invention further provides saturated ethers of said formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m) R² _(a). Included are saturated ethers of said formula where X, R¹, R², a, m, and n are defined as above, provided that when each X is F, a is 0, m is 1, and n is 0, then R¹ is other than F; and when each X is F, R¹ is --(CF₂)_(p) H, a is 0, m is 1 and n is 0, then p is other than 1.

This invention also provides a process for preparing unsaturated ethers of the formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F) _(m-q) (C₂ H_(n-1) X_(3-n) F)_(q) R² _(a) wherein R¹, R², X, a, m, and n are as indicated above, and q is an integer from 1 to m. The process comprises contacting a saturated ether of the formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m) R² _(a), provided that C₂ H_(n) X_(4-n) F is selected from the group consisting of --CClFCClF₂, --CCl₂ CCl₂ F, --CHClCCl₂ F, --CHClCHClF and --CCl₂ CHClF, with a dehalogenation catalyst

This invention still further provides unsaturated ethers of said formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m-q) (C₂ H_(n-1) X_(3-n) F)_(q) R² _(a). Included are unsaturated ethers of said formula where X, R¹, R², a, m, n and q are as defined above, provided that when each X is F, a is 0, m is 1, n is 0 and q is 1, then R¹ is other than F.

DETAILED DESCRIPTION OF THE INVENTION

It has been found that surprisingly, certain fluoroethers do not decompose upon contact with the Lewis acid, SbF₅. Instead, the Lewis acid catalyses the addition of the fluoroether to selected olefins.

Examples of olefins of the formula C₂ H_(n) X_(4-n) which can be used to prepare adducts in accordance with one aspect of this invention include CF₂ ═CF₂, CClF═CF₂, CCl₂ ═CF₂, CClF═CClF, CHF═CHF, CH₂ ═CF₂, CHF═CF₂, CBrF═CF₂, CCl₂ ═CCl₂, CHCl═CCl₂, CH₂ ═CCl₂ and CHCl═CHCl. Most of the olefins are commercially available (e.g., CH₂ ═CF₂), the others can be prepared by known methods.

Certain ether starting materials which are useful in the process of this invention for preparing saturated ether adducts (e.g., HCF₂ CF₂ CH₂ OCF₃, CF₃ CH₂ OCHF₂, CF₃ CH₂ OCF₃, CF₃ CHFCF₂ CH₂ OCF₃ and H(CF₂)₄ CH₂ OCF₃) can be prepared by the method described in U.S. Pat. No. 5,382,704. Other ethers useful in this process, such as CF₃ CH₂ OCF₂ CHF₂, CF₃ CH₂ OCF₂ CHFCF₃, CF₃ CH₂ OCF₂ CHFOCF₃, CF₃ CH₂ OCF₂ CHFOC₃ F₇ and CF₃ CH₂ OCF₂ CHClF, can be prepared by the nucleophilic addition of fluoroalcohols to fluoroolefins and fluoroalkylvinyl ethers as shown in equation (1) (see Henne et al., J. Am. Chem. Soc. 72, 4378 (1950).

    CF.sub.3 CH.sub.2 OH+NaOH+CFZ═CF.sub.2 →CF.sub.3 CH.sub.2 OCF.sub.2 CHFZ                                            (1)

Z may be selected from the group consisting of --F, --CF₃, --OCF₃, --OC₃ F₇ and --Cl. The reaction is typically done in the temperature range of 50° C. to 100° C.

Solvents or diluents may be employed for the catalyzed addition reaction of the present invention. The solvent or diluent is selected so that it will not be reactive in the process or lead to the deactivation of the antimony fluoride catalyst. Suitable solvents or diluents include those selected from the group consisting of perfluoroalkanes, (e.g., perfluorocyclobutane) the cyclic dimers of hexafluoropropene (i.e., the isomeric perfluorodimethylcyclobutanes), perfluoroethers and perfluoro tertiary amines. Preferred on the basis of its ready availability to those skilled in the art are the cyclic dimers of hexafluoropropene.

When the addition product (adduct) contains chlorine, the chlorine can be removed by either reaction with HF in the presence of a fluorination catalyst (e.g., Cr₂ O₃) or by reaction with hydrogen in the presence of a hydrogenation catalyst (e.g., palladium supported on carbon). The adduct is thereby converted from a fluoroether containing chlorine to a fluoroether containing only hydrogen, oxygen, carbon and fluorine.

A suitable temperature range for this process of preparing saturated ether adducts is from about 0° C. to about 100° C. A preferred temperature range is from about 10° C. to 50° C.

Reaction time is not critical and typically ranges from about one hour to about 24 hours. From about 1 to 10 hours is usually sufficient.

The pressure employed for this process of preparing saturated ether adducts is not critical. The reaction is normally run at pressures in the range of about 15 to 300 psig (101 kPa to 2169 kPa). Autogenous pressures are usually employed; however, the pressure should not be allowed to rise above 300 psig (2169 kPa) when using tetrafluoroethylene because of safety considerations.

Where the reaction conditions are heterogeneous, some degree of agitation is often desirable.

Since the catalysts are water sensitive, reagents and equipment should be dried before use.

The proportion of the SbF₅ catalyst to the olefin reactant on a molar basis is typically about 0.5:1 to about 20:1; a range of about 1:1 to about 10:1 is preferred.

The proportion of the fluorinated ether to olefin on a molar basis is normally at least about 1:1. Of note are embodiments which use fluorinated ethers as a solvent such that they are present in substantial excess.

Examples of unique adducts which can be prepared using this invention include HCF₂ CF₂ CH₂ OCF(C₂ F₅)₂, (which can be prepared from HCF₂ CF₂ CH₂ OCF₃ and CF₂ ═CF₂ (i.e., TFE)); CF₃ CH₂ OCHFC₂ F₅ (which can prepared from CF₃ CH₂ OCHF₂ and TFE); CF₃ CH₂ OCH(C₂ F₅)₂ (which can be prepared from CF₃ CH₂ OCHF₂ and TFE); CF₃ CH₂ OCF(C₂ F₅)CHF₂ (which can be prepared from CF₃ CH₂ OCF₂ CHF₂ and TFE); CF₃ CH₂ OCF(C₂ F₅)₂ (which can be prepared from CF₃ CH₂ OCF₃ and TFE); CF₃ CHFCF₂ CH₂ OC₃ F₇ (which can be prepared from CF₃ CHFCF₂ CH₂ OCF₃ and TFE); CF₃ CHFCF₂ CH₂ OCF(C₂ F₅)₂ (which can be prepared from CF₃ CHFCF₂ CH₂ OCF₃ and TFE); H(CF₂)₄ CH₂ OC₃ F₇ (which can be prepared from H(CF₂)₄ CH₂ OCF₃ and TFE); H(CF₂)₄ CH₂ OCF(C₂ F₅)₂ (which can be prepared from H(CF₂)₄ CH₂ OCF₃ and TFE); CF₃ CH₂ OCF(C₂ F₅)CHFCF₃ (which can be prepared from CF₃ CH₂ OCF₂ CHFCF₃ and TFE); CF₃ CH₂ OCF(C₂ F₅)CHFOCF₃ (which can be prepared from CF₃ CH₂ OCF₂ CHFOCF₃ and TFE); CF₃ CH₂ OCF(C₂ F₅)CHFOC₃ F₇ (which can be prepared from CF₃ CH₂ OCF₂ CHFOC₃ F₇ and TFE); CF₃ CH₂ OCF(C₂ F₅)CHClF (which can be prepared from CF₃ CH₂ OCF₂ CHClF and TFE); CF₃ CH₂ OC(C₂ HF₄)₂ CHF₂ (which can be prepared from CF₃ CH₂ OCF₂ CHF₂ and CHF═CF₂); CF₃ CH₂ OCF(C₂ ClF₄)CHF₂ (which can be prepared from CF₃ CH₂ OCF₂ CHF₂ and CClF═CF₂); CF₃ CH₂ OCHFCClFCClF₂ (which can be prepared from CF₃ CH₂ OCHF₂ and CClF═CClF); CF₃ CH₂ OCF₂ CClFCClF₂ (which can be prepared from CF₃ CH₂ OCF₃ and CClF═CClF); CF₃ CH₂ OCF(CClFCClF₂)CHFCF₃ (which can be prepared from CF₃ CH₂ OCF₂ CHFCF₃ and CClF═CClF); and CF₃ CH₂ OCF(CClFCClF₂)CHFOCF₃ (which can be prepared from CF₃ CH₂ OCF₂ CHFOCF₃ and CClF═CClF).

Another embodiment of this invention provides a process for the dehalogenation of ethers of said formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m) R² _(a) to produce unsaturated ethers. The saturated ethers of the disclosed formula can be prepared by the same general reaction as described above. For example, a fluorinated ether of the formula R¹ CF₂ CH₂ OCF_(3-a) R² _(a) can be reacted with an olefin selected from the group consisting of CClF═CClF, CCl₂ ═CCl₂, CHCl═CHCl and CHCl═CCl₂ to produce the following chlorofluorinated ether adducts, R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ Cl₂ F₃)_(m) R² _(a), R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ Cl₄ F)_(m) R² _(a), R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H₂ Cl₂ F)_(m) R² _(a) and R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ HCl₃ F)_(m) R² _(a), respectively.

The dehalogenation reaction of this process (i.e., the elimination of two chlorine atoms with the formation of an olefinic bond) can be done by treating he chlorofluorinated ether adducts by procedures well known in the art. Suitable procedures include treatment with zinc metal in alcohols, ethers, dioxane or other solvents; and heterogeneous dehalogenation reactions achieved by contacting the chlorofluorinated ether adducts and hydrogen with palladium or rhenium catalysts. Respective products of the dehalogenation reaction of the above chlorofluorinated ether adducts can include R¹ CF₂ CH₂ OCF_(3-a-m) (CF═CF₂)_(m) R² _(a), R¹ CF₂ CH₂ OCF_(3-a-m) (CCl═CClF)_(m) R² _(a), R¹ CF₂ CH₂ OCF_(3-a-m) (CH═CHF)_(m) R² _(a) and R¹ CF₂ CH₂ OCF_(3-a-m) (CH═CClF)_(m) R² _(a).

Examples of unique unsaturated ethers which can be prepared using this invention include CF₃ CH₂ OCHFCF═CF₂ (which can be prepared by dechlorination of an adduct prepared from CF₃ CH₂ OCHF₂ and CClF═CClF); CF₃ CH₂ OCF(CF═CF₂)CHFCF₃ (which can be prepared by dechlorination of an adduct prepared from CF₃ CH₂ OCF₂ CHFCF₃ and CClF═CClF); and CF₃ CH₂ OCF(CF═CF₂)CHFOCF₃ (which can be prepared by dechlorination of an adduct prepared from CF₃ CH₂ OCF₂ CHFOCF₃ and CClF═CClF).

The dehalogenation reaction can be done in batch, semi-batch, semi-continuous or continuous modes in one or more reaction vessels. On a laboratory scale, the reaction can be done in shaker tubes, where all reagents are combined before the reaction vessel is sealed and the reaction begun. It can also be done in autoclaves equipped with an agitator. Product(s) may be isolated by standard chemical engineering techniques, e.g., fractional distillation.

Without further elaboration, it is believed that one skilled in the art can, using the description herein, utilize the present invention to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and does not constrain the remainder of the disclosure in any way whatsoever.

EXAMPLES Example 1 Reaction of HCF₂ CF₂ CH₂ OCF₃ With Tetrafluoroethylene (TFE)

HCF₂ CF₂ CH₂ OCF₃ (50 g, 0.25 mol), SbF₅ (15 g, 0.07 mol) and TFE 50 g (0.5 mol) were charged into a 400 mL Hastelloy™ nickel alloy tube and agitated at 25° C. for 12 hours. The reaction mixture was poured onto ice, the organic (lower) layer was separated and dried over P₂ O₅. Fractionation of the liquid product gave HCF₂ CF₂ CH₂ OCF₂ CF₂ CF₃, 15.2 g (41% yield), b.p. 77.5-78° C. and HCF₂ CF₂ CH₂ OCF(C₂ F₅)₂, 29.3 g (57% yield), b.p. 113.5-114.5° C. (see Table 1). Polytetrafluoroethylene (PTFE), 5 g was also isolated.

Example 2 Reaction of CF₃ CH₂ OCF₂ H With Tetrafluoroethylene (TFE)

CF₃ CH₂ OCF₂ H (50 g, 0.33 mol), TFE (50 g, 0.5 mol) and SbF₅ (20 g, 0.09 mol) were charged into a 400 mL Hastelloy™ nickel alloy tube and agitated at 25° C. for 12 hours. Distillation of the liquid product (58 g) gave CF₃ CH₂ OCFHC₂ F₅, 34.3 g (51.5% yield based on converted starting ether), b.p. 74.8° C., and CF₃ CH₂ OCH(C₂ F₅)₂ 7.8 g (33% yield), b.p. 98.8-99.2° C. (see Table 1). The formation of PTFE (25 g) was also observed.

Example 3 Reaction of CF₃ CH₂ OCF₂ CF₂ H With Tetrafluoroethylene (TFE)

CF₃ CH₂ OCF₂ CF₂ H (60 g, 0.3 mol), SbF₅ (10 g, 0.045 mol) and TFE (20 g, 0.2 mol) were charged into a 400 mL Hastelloy™ nickel alloy tube and agitated at 25° C. for 12 hours. Fractionation of the liquid product gave CF₃ CH₂ OCF(C₂ F₅)CF₂ H, 42 g (46.4% yield), b.p. 65.2-65.8° C. (see Table 1). No formation of PTFE was observed.

Example 4 Reaction of CF₃ CH₂ OCF₂ CF₂ H With Trifluoroethylene

Trifluoroethylene (16.4 g, 0.2 mol) was bubbled through a solution of SbF₅ (10 g, 0.045 mol) into CF₃ CH₂ OCF₂ CF₂ H (20 g, 0.1 mol) for 3 hours and the temperature maintained below 35° C. The reaction mixture was washed with water, dried and analyzed. The crude product (24 g) was a mixture containing of starting ether (8%), CF₃ CH₂ OCF(CFHCF₃)CF₂ H (10%) and CF₃ CH₂ OC(CFHCF₃)₂ CF₂ H (82%) (see Table 1). The latter product (mixture of diastereomers) was isolated by distillation, b.p. 1 14-120° C., the yield was 61%.

Example 5 Reaction of CF₃ CH₂ OCF₂ H With CFCl═CFCl

CFCl═CFCl (25 g, 0.2 mol ) was added dropwise over the course of an hour to a stirred mixture of CF₃ CH₂ OCF₂ H (50 g, 0.33 mol) and SbF₅ (8 g, 0.037 mol) at 10-20° C. The reaction mixture was stirred for another 30 minutes at room temperature after the addition was finished. It was then poured onto ice and the organic layer was separated, dried over P₂ O₅ and distilled to give CF₃ CH₂ OCFHCFClCF₂ Cl (mixture of diastereomers) 25 g (43%), b.p. 55-58° C./25 mm Hg (3.3 kPa) (see Table 1).

Example 6 Preparation of CF₃ CH₂ OCF(CF═CF₂)CFHCF₃

A mixture of Zn dust (7 g), C₂ H₅ OH (50 mL) and CF₃ CH₂ OCF(CFClCF₂ Cl)CFHCF₃ (15 g) was heated at reflux for 1 hour. The reaction mixture was cooled to 25° C., decanted and the solid washed twice with alcohol. The combined solution was poured into diluted (5%) hydrochloric acid and the organic layer was separated, washed with water, dried over P₂ O₅ and distilled to give CF₃ CH₂ OCF(CF═CF₂)CFHCF₃ 10 g (83%) (see Table 1.)

Comparative Example A Reaction of ClCF₂ CH₂ OCF₂ CF₂ H With SbF₅

ClCF₂ CH₂ OCF₂ CF₂ H (3 mmol) was slowly added to a solution of SbF₅ (2 g) in SO₂ ClF (12 mmol) at -78° C. The reaction mixture was mixed by shaking and analyzed by ¹⁹ F NMR at -40° C. After 20 minutes the reaction mixture did not contain any of the starting ether, but only CF₃ H and CF₃ CH₂ Cl in a 1:1 molar ratio.

Comparative Example B Reaction of C₃ F₇ OCHFCF₃ +TFE+SbF₅

The apparatus and procedure of Example 1 was used. C₃ F₇ OCHFCF₃ (200 g) was contacted with TFE (30 g) in the presence of SbF₅ (10 g) at 25° C. for 12 hours. No condensation product was found in the crude reaction mixture. The starting ether (60%) was recovered along with PTFE (25 g).

The results obtained from Comparative Examples A and B contrast with the results of reactions in accordance with this invention which form adducts rather than degradation products. Additional examples of reactions in accordance with the present invention (Nos. 7 through 18) are summarized in Table 1.

                                      TABLE 1                                      __________________________________________________________________________     Condensation of Polyfluorinated Ethers with Fluoroolefins Catalyzed by         SbF.sub.5                                                                      Ex.                                                                               SbF.sub.5                                                                          Reactants  Temp (° C.)                                                                   Products            Anal. or MS                          No. (wt. %) (mol. ratio) Time (h) (% yield) b.p. (° C.) found                                                     (calcd.)                           __________________________________________________________________________     1  13  HCF.sub.2 CF.sub.2 CH.sub.2 OCF.sub.3 +                                                   25(12)                                                                               HCF.sub.2 CF.sub.2 CH.sub.2 OC.sub.3 F.sub.7                                               77.5-77.9                                                                              C, 23.13 (24.00), H, 0.99                                                         TFE(1:2)  (41),  (1.00);                                                    F, 69.85 (69.67)                         HCF.sub.2 CF.sub.2 CH.sub.2 OCF- 113.5-114.5 C, 22.96 (24.00)                                                        H,0.74                                   (C.sub.2 F.sub.5).sub.2 (57)  (0.75); F, 72.36 (71.25)                     2 17 CF.sub.3 CH.sub.2 OCF.sub.2 H + 25(12) CF.sub.3 CH.sub.2 OCFHC.sub.                                                 2 F.sub.5 (52) 74.8 C, 23.34                                                   (24.00); H, 1.19                       TFE (3:2)  CF.sub.3 CH.sub.2 OCH-  (1.20); F, 69.78 (68.40)                      (C.sub.2 F.sub.5).sub.2 (33) 99.2 C, 23.43 (24.00); H, 0.87                                                                 (0.86); F, 72.29                                                        (70.57)                              3 11 CF.sub.3 CH.sub.2 OCF.sub.2 CF.sub.2 H + 25(14) CF.sub.3 CH.sub.2                                                   OCF (C.sub.2 F.sub.5)-                                                         65.2-65.8 C, 23.81 (24.00);                                                    H, 0.99                                TFE (3:2)  CF.sub.2 H (70)  (1.00); F, 69.97 (69.67)                         4 20 CF.sub.3 CH.sub.2 OCF.sub.2 CF.sub.2 H + 25-30(4) CF.sub.3                                                          CH.sub.2 OC(CFHCF.sub.3                                                        ).sub.2 - 114-120 C, 26.47                                                     (26.37); H, 1.58                       C.sub.2 F.sub.3 H.sup.a (1:2)  CF.sub.2 H(61)  (1.37); F, 69.26                                                        (67.86)                              5 10 CF.sub.3 CH.sub.2 OCF.sub.2 H + 10-30 (3) CF.sub.3 CH.sub.2                                                         OCFHCFCl- 55.7-56.7/25 mm C,                                                   20.98 (21.20); H, 0.90                                                            C.sub.2 F.sub.2 Cl.sub.2                                                    .sup.b (3:2)  CF.sub.2 Cl                                                      (43) (3.3 kPa) (1.06); F,                                                      47.11 (46.97);                             Cl, 24.82 (25.09)                                                        6 -- CF.sub.3 CH.sub.2 OCF(CFCl- reflux CF.sub.3 CH.sub.2 --OCF(CF═C                                                 F.sub.2)- 108-110 C, 26.72                                                     (26.92); H, 0.96                       CF.sub.2 Cl)CFHCF.sub.3 + Zn  CFHCF.sub.3 (83)  (1.09); F, 66.63                                                       (66.98)                                + C.sub.2 H.sub.5 OH                                                         7 5 CF.sub.3 CH.sub.2 OCF.sub.3 + 25 (12) CF.sub.3 CH.sub.2 OC.sub.3                                                     F.sub.7 (5), -- --                     TFE(3:2)  CF.sub.3 CH.sub.2 OCF(C.sub.2 F.sub.5).sub.2 (9) -- --                                                        8 8 CF.sub.3 CFHCF.sub.2                                                      CH.sub.2 OCF.sub.3 25 (12)                                                     CF.sub.3 CFHCF.sub.2 CH.sub.2                                                  OCF.sub.2 - -- --                      + TFE(1:1)  C.sub.2 F.sub.5 (10) 125 --                                          CF.sub.3 CFHCF.sub.2 CH.sub.2 OCF-                                             (C.sub.2 F.sub.5).sub.2 (50)                                               9 16  H(CF.sub.2 CF.sub.2).sub.2 CH.sub.2 OCF.sub.3 25 (12) H(CF.sub.2                                                   CF.sub.2).sub.2 CH.sub.2                                                       O--C.sub.3 F.sub.7 -- m/e                                                      (M-F) 380.9983                         + TFE(1:1)  (10)  (380.9960)                                                     H(CF.sub.2 CF.sub.2).sub.2 CH.sub.2 O--CF- -- m/e (M-F) 480.9973                                                          (C.sub.2 F.sub.5).sub.2                                                   (6.8)  (489.9996)                    10  11  CF.sub.3 CH.sub.2 OCF.sub.2 CF.sub.2 H + 25 (14) CF.sub.3                                                        CH.sub.2 OCF(C.sub.2 F.sub.4                                                   Cl)- 72-75 C, 22.76 (22.75);                                                   H, 0.95                                C.sub.2 F.sub.3 Cl.sup.c (1:1)  CF.sub.2 H.sup.d (48)  (1.14); F,                                                      60.25 (60.03)                        11  9 CF.sub.3 CH.sub.2 OCF.sub.2 CFHCF.sub.3 25 (14) CF.sub.3 CH.sub.2                                                  OCF(C.sub.2 F.sub.5)- 90.3-91                                                    C, 23.85 (24.00); H, 0.86                                                       + TFE (1:1)  CFHCF.sub.3                                                    (57.5)  (1.01); F, 69.18                                                       (70.07)                              12  6 CF.sub.3 CH.sub.2 OCF.sub.2 CFHO- 25 (14) CF.sub.3 CH.sub.2                                                        --OCF(C.sub.2 F.sub.5)- 98-99                                                  C, 21.71 (22.95); H, 0.90                                                         CF.sub.3 + TFE (1:1)                                                        CFHOCF.sub.3 (42)  (0.82); F,                                                  67.67 (67.49)                            C.sub.8 H.sub.3 F.sub.13 O.sub.2.sup.e (6.2) 112 C, 24.16 (25.41);                                                   H, 0.78                                    (0.80); F, 66.73 (65.34)                                                       m/e. 377.9883 (377.9925)                                                 13  7 CF.sub.3 CH.sub.2 OCF.sub.2 CFHO- 25 (14) CF.sub.3 CH.sub.2                                                        OCF(C.sub.2 F.sub.5)- 122-126                                                  m/e 446.9842(446.9878)                                                            C.sub.3 F.sub.7 + TFE(1:1)                                                   CFHOC.sub.3 F.sub.7 (22)                                                       14  16  CF.sub.3 CH.sub.2                                                     OCF.sub.2 CFClH 25 (14)                                                        CF.sub.3 CH.sub.2 OCF(C.sub.2                                                  F.sub.5)- 106-109 --                   + TFE(1:1)  CFClH(62)                                                        15  10  CF.sub.3 CH.sub.2 OCF.sub.2 CF.sub.2 H 10-35 CF.sub.3 CH.sub.2                                                   OCF(CFCl- 50-51/25 mm C,                                                       22.70 (22.77); H, 0.97                                                            + C.sub.2 F.sub.2 Cl.sub.2                                                  (1:1)  CF.sub.2 Cl)CF.sub.2                                                    H(53) (3.3 kPa) (0.96); Cl,                                                    11.45 (11.20)                        16  6 CF.sub.3 CH.sub.2 OCF.sub.3  10-20 CF.sub.3 CH.sub.2 OCF.sub.2                                                     CFCl- -- C, 21.77 (21.64); H,                                                  1.05                                   + C.sub.2 F.sub.2 Cl.sub.2 (2:1)  CF.sub.2 Cl(17).sup.f  (0.91)                                                         17  6 CF.sub.3 CH.sub.2                                                       OCF.sub.2 CFHCF.sub.3  10-25                                                   CF.sub.3 CH.sub.2 OCF(CFClCF.s                                                 ub.2 55-56.4/25 mm C, 21.15                                                    (21.95); H, 0.82                       + C.sub.2 F.sub.2 Cl.sub.2 (2:1)  Cl)CFHCF.sub.3 (42%) (3.3 kPa)                                                       (0.79); F, 54.34 (54.57);                                                             Cl, 19.29(18.51)                                                         18  7 CF.sub.3 CH.sub.2                                                       OCF.sub.2 CFHO- 10-15°                                                  C. CF.sub.3 CH.sub.2 OCF(CFCl-                                                  54-57/25 mm C, 21.22                                                          (21.07); H, 0.67                       CF.sub.3 + C.sub.2 F.sub.2 Cl.sub.2 (2:1)  CF.sub.2 Cl)CFHO--CF.sub.3                                                  (43%) (3.3 kPa) (0.76)             __________________________________________________________________________      .sup.a CFH═CF.sub.2                                                        .sup.b CFCl═CFCl                                                           .sup.c CF.sub.2 ═CFCl                                                      .sup.d mixture of isomers CF.sub.3 CH.sub.2 OCF(CFClCF.sub.3)CF.sub.2 H        and CF.sub.3 CH.sub.2 OCF(CF.sub.2 CF.sub.2 Cl)CF.sub.2 H in ratio 69:31       .sup.e                                                                         ##STR1##                                                                       .sup.f yield is based on NMR data                                         

I claim:
 1. A process for preparing an adduct of the formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m) R² _(a) wherein R¹ is selected from the group consisting of --(CF₂)_(p) H and --C_(p) F_(2p+1) where p is 0 or an integer from 1 to 6; R² is selected from the group consisting of --H, --CHF₂, --CHFCF₃, --CHFOCF₃, --CHFO(CF₂)₂ CF₃, and --CHClF; each X is independently selected from the group consisting of Br, Cl and F; a is 0 or 1; m is 1 or 2, provided that when a is 1 and R² is other than hydrogen, then m is 1; and n is 0, 1 or 2, comprising:reacting a fluorinated ether of the formula R¹ CF₂ CH₂ OCF_(3-a) R² _(a) with an olefin of the formula C₂ H_(n) X_(4-n) in the liquid phase in the presence of antimony pentafluoride catalyst.
 2. The process of claim 1 wherein HCF₂ CF₂ CH₂ OCF₂ CF₂ CF₃ is prepared by reacting HCF₂ CF₂ CH₂ OCF₃ with C₂ F₄.
 3. A saturated ether of the formula:

    R.sup.1 CF.sub.2 CH.sub.2 OCF.sub.3-a-m (C.sub.2 H.sub.n X.sub.4-n F).sub.m R.sup.2.sub.a

wherein R¹ is selected from the group consisting of --(CF₂)_(p) H and --C_(p) F_(2p+1) where p is 0 or an integer from 1 to 6; R² is selected from the group consisting of --H, --CHF₂, --CHFCF₃, --CHFOCF₃, --CHFO(CF₂)₂ CF₃, and --CHClF; each X is independently selected from the group consisting of Br, Cl and F; a is 0 or 1; m is 1 or 2, provided that when a is 1 and R² is other than hydrogen, then m is 1; and n is 0, 1 or 2; provided that when each X is F, a is 0, m is 1, and n is 0, then R¹ is other than F; and when each X is F, R¹ is --(CF₂)_(p) H, a is 0, m is 1 and n is 0, then p is other than
 1. 4. A saturated ether of claim 3 selected from the group consisting of HCF₂ CF₂ CH₂ OCF(C₂ F₅)₂, CF₃ CH₂ OCHFC₂ F₅, CF₃ CH₂ OCH(C₂ F₅)₂, CF₃ CH₂ OCF(C₂ F₅)CHF₂, CF₃ CH₂ OCF(C₂ F₅)₂, CF₃ CHFCF₂ CH₂ OC₃ F₇, CF₃ CHFCF₂ CH₂ OCF(C₂ F₅)₂, H(CF₂)₄ CH₂ OC₃ F₇, H(CF₂)₄ CH₂ OCF(C₂ F₅)₂, CF₃ CH₂ OCF(C₂ F₅)CHFCF₃, CF₃ CH₂ OCF(C₂ F₅)CHFOCF₃, CF₃ CH₂ OCF(C₂ F₅)CHFOC₃ F₇, CF₃ CH₂ OCF(C₂ F₅)CHClF, CF₃ CH₂ OC(C₂ HF₄)₂ CHF₂, CF₃ CH₂ OCF(C₂ ClF₄)CHF₂, CF₃ CH₂ OCHFCClFCClF₂, CF₃ CH₂ OCF₂ CClFCClF₂, CF₃ CH₂ OCF(CClFCClF₂)CHFCF₃, and CF₃ CH₂ OCF(CClFCClF₂)CHFOCF₃.
 5. A process for preparing unsaturated ethers of the formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m-q) (C₂ H_(n-1) X_(3-n) F)_(q) R² _(a) wherein R¹ is selected from the group consisting of --(CF₂)_(p) H and --C_(p) F_(2p+1) where p is 0 or an integer from 1 to 6; R² is selected from the group consisting of --H, --CHF₂, --CHFCF₃, --CHFOCF₃, --CHFO(CF₂)₂ CF₃, and --CHClF; each X is independently selected from the group consisting of Br, Cl and F; a is 0 or 1; m is 1 or 2, provided that when a is 1 and R² is other than hydrogen, then m is 1; n is 0, 1 or 2; and q is an integer from 1 to m, comprising:contacting a saturated ether of the formula R¹ CF₂ CH₂ OCF_(3-a-m) (C₂ H_(n) X_(4-n) F)_(m) R² _(a), provided that C₂ H_(n) X_(4-n) F is selected from the group consisting of--CClFCClF₂, --CCl₂ CCl₂ F, --CHClCCl₂ F, --CHClCHClF and --CCl₂ CHClF, with a dehalogenated catalyst.
 6. The process of claim 5 wherein CF₃ CH₂ OCF(CF═CF₂)CFHCF₃ is prepared by reacting CF₃ CH₂ OCF(CFClCF₂ Cl)CFHCF₃.
 7. The process of claim 5 wherein the saturated ether is prepared by reacting a fluorinated ether of the formula R¹ CF₂ CH₂ OCF_(3-a) R² _(a) with an olefin of the formula C₂ H_(n) X_(4-n) in the liquid phase in the presence of antimony pentafluoride catalyst.
 8. The process of claim 7 wherein CF₃ CH₂ OCF(CFClCF₂ Cl)CFHCF₃ is prepared by reacting CF₃ CH₂ OCF₂ CFHCF₃ with C₂ F₂ Cl₂ ; and CF₃ CH₂ OCF(CF═CF₂)CFHCF₃ is prepared by dechlorination of said CF₃ CH₂ OCF(CFClCF₂ Cl)CFHCF₃.
 9. An unsaturated ether of the formula:

    R.sup.1 CF.sub.2 CH.sub.2 OCF.sub.3-a-m (C.sub.2 H.sub.n X.sub.4-n F).sub.m-q (C.sub.2 H.sub.n-1 X.sub.3-n F).sub.q R.sup.2.sub.a

wherein R¹ is selected from the group consisting of--(CF₂)_(p) H and --C_(p) F_(2p+1) where p is 0 or an integer from 1 to 6; R² is selected from the group consisting of --H, --CHF₂, --CHFCF₃, --CHFOCF₃, --CHFO(CF₂)₂ CF₃, and --CHClF; each X is independently selected from the group consisting of Br, Cl and F; a is 0 or 1; m is 1 or 2, provided that when a is 1 and R² is other than hydrogen, then m is 1; n is 0, 1 or 2; and q is an integer from 1 to m; provided that when each X is F, a is 0, m is 1, n is 0 and q is 1, then R¹ is other than F.
 10. An unsaturated ether of claim 9 selected from the group consisting of CF₃ CH₂ OCHFCF═CF₂, CF₃ CH₂ OCF(CF═CF₂)CHFCF₃, and CF₃ CH₂ OCF(CF═CF₂)CHFOCF₃. 